bug#51296: [PATCH] Add WebP format support

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Fri, 22 Oct 2021 02:03:22 -0700
> Cc: 51296@debbugs.gnu.org
> 
> close 51296 29.1
> thanks
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Please go ahead, and thanks.
> 
> Now pushed to master (commit bc2a5c1127).

Thanks.  This has some issues, and currently won't work on MS-Windows.
I'm working on that.